OPENJPA-235 SQL reordering to avoid non-nullable foreign key constraint violations

Fix problem in deletion for foreign key on delete cascade.
Commit openjpa-235-delete-cascade.patch provided by Fay Wang.

git-svn-id: https://svn.apache.org/repos/asf/openjpa/trunk@673258 13f79535-47bb-0310-9956-ffa450edef68

openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/meta/strats/RelationFieldStrategy.java

@@ -256,7 +256,8 @@ public class RelationFieldStrategy
             if (rel != null) {
                 ForeignKey fk = field.getForeignKey((ClassMapping)
                     rel.getMetaData());
-                if (fk.getDeleteAction() == ForeignKey.ACTION_RESTRICT) {
+                if (fk.getDeleteAction() == ForeignKey.ACTION_RESTRICT ||
+                    fk.getDeleteAction() == ForeignKey.ACTION_CASCADE) {
                     Row row = field.getRow(sm, store, rm, Row.ACTION_DELETE);
                     row.setForeignKey(fk, null, rel);
                 }

openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/PrimaryRow.java

@@ -192,10 +192,10 @@ public class PrimaryRow
     }
 
     /**
-     * If this is a delete, delay foreign keys to other deleted objects if
+     * If this is a delete, delay foreign keys to other deleted objects if the 
-     * the key is restricted. If this is an update or insert, delay foreign
+     * key is restricted or cascade. If this is an update or insert, delay 
-     * keys to other inserts if the key is not logical. If the foreign key
+     * foreign keys to other inserts if the key is not logical. If the foreign 
-     * is to a new record and the columns are auto-inc, record it.
+     * key is to a new record and the columns are auto-inc, record it.
      */
     private boolean delayForeignKey(ForeignKey fk, OpenJPAStateManager sm,
         boolean set) {
@@ -204,7 +204,8 @@ public class PrimaryRow
 
         if (getAction() == ACTION_DELETE)
             return sm.isDeleted() && !fk.isDeferred()
-                && fk.getDeleteAction() == ForeignKey.ACTION_RESTRICT;
+                && (fk.getDeleteAction() == ForeignKey.ACTION_RESTRICT ||
+                    fk.getDeleteAction() == ForeignKey.ACTION_CASCADE);
 
         if (!sm.isNew() || sm.isFlushed())
             return false;

openjpa-persistence-jdbc/src/test/java/org/apache/openjpa/jdbc/kernel/EntityF.java

@@ -0,0 +1,43 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.openjpa.jdbc.kernel;
+import java.util.List;
+
+import javax.persistence.*;
+
+@Entity
+public class EntityF  {
+	@Id private int id;
+
+	@OneToMany(cascade=CascadeType.ALL, mappedBy="entityF")
+	private List<EntityG> listG;
+	
+	public List<EntityG> getListG() {
+		return listG;
+	}
+	public void setListG(List<EntityG> listG) {
+		this.listG = listG;
+	}
+	public int getId() {
+		return id;
+	}
+	public void setId(int id) {
+		this.id = id;
+	}
+}

openjpa-persistence-jdbc/src/test/java/org/apache/openjpa/jdbc/kernel/EntityG.java

@@ -0,0 +1,49 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.openjpa.jdbc.kernel;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
+
+import org.apache.openjpa.persistence.jdbc.ForeignKey;
+import org.apache.openjpa.persistence.jdbc.ForeignKeyAction;
+
+@Entity
+public class EntityG  {
+	@Id private int id;
+
+	@ForeignKey(deleteAction=ForeignKeyAction.CASCADE)
+	@ManyToOne (cascade=CascadeType.MERGE)	
+	private EntityF entityF;
+	
+	public EntityF getEntityF() {
+		return entityF;
+	}
+	public void setEntityF(EntityF entityF) {
+		this.entityF = entityF;
+	}
+	public int getId() {
+		return id;
+	}
+	public void setId(int id) {
+		this.id = id;
+	}
+}

openjpa-persistence-jdbc/src/test/java/org/apache/openjpa/jdbc/kernel/TestNoForeignKeyViolation.java

@@ -18,6 +18,8 @@
  */
 package org.apache.openjpa.jdbc.kernel;
 
+import java.util.ArrayList;
+import java.util.List;
 import javax.persistence.EntityManager;
 
 import org.apache.openjpa.persistence.test.SingleEMFTestCase;
@@ -37,7 +39,8 @@ public class TestNoForeignKeyViolation
     private EntityD entityD;
 
     public void setUp() {
-        setUp(EntityA.class, EntityB.class, EntityC.class, EntityD.class, EntityE.class);
+        setUp(EntityA.class, EntityB.class, EntityC.class, EntityD.class, 
+              EntityE.class, EntityF.class, EntityG.class);
 
         createTestData();
     }
@@ -154,4 +157,55 @@ public class TestNoForeignKeyViolation
             em.close();
         }
     }
+    
+    public void testForeignKeyCascade() {
+        EntityManager em = emf.createEntityManager();
+        try {
+            EntityF f = new EntityF();
+            f.setId(1);
+
+            List<EntityG> listG = new ArrayList<EntityG>();
+            EntityG g1 = new EntityG();
+            g1.setId(1);
+            listG.add(g1);
+            g1.setEntityF(f);
+            
+            EntityG g2 = new EntityG();
+            g2.setId(2);
+            listG.add(g2);
+            g2.setEntityF(f);
+
+            EntityG g3 = new EntityG();
+            g3.setId(3);
+            listG.add(g3);
+            g3.setEntityF(f);
+
+            EntityG g4 = new EntityG();
+            g4.setId(4);
+            listG.add(g4);
+            g4.setEntityF(f);
+            
+            f.setListG(listG);
+            em.getTransaction().begin();
+            em.persist(f);
+            em.persist(g1);
+            em.persist(g2);
+            em.persist(g3);
+            em.persist(g4);
+            em.getTransaction().commit();
+
+            em.getTransaction().begin();
+            em.remove(f);
+            em.getTransaction().commit();
+        }
+        catch (Exception e) {
+            fail("Fail to delete EntityF");
+        }
+        finally {
+            if (em.getTransaction().isActive())
+                em.getTransaction().rollback();
+            em.close();
+        }
+    }
+    
 }